The present invention relates to an ink-jet recording apparatus, a recording head and a recording head cartridge thereof.
Impact and nonimpact recording schemes are available as recording schemes. Among these schemes, the nonimpact recording schemes include electrophotographic, electrostatic, thermal, and ink-jet recording schemes.
Of these nonimpact recording schemes, the ink-jet recording scheme is regarded as the most excellent for its advantages, i.e., low noise, low power, compactness, multi-color constitution, and inexpensive components.
In general, the ink-jet recording scheme is to print an image on recording paper by injecting small ink droplets from capillary nozzles to the paper.
According to the ink-jet recording scheme, various prior systems have been proposed. A first example is a system for instantaneously increasing the pressure of a liquid ink by utilizing vibrations of a piezoelectric element in an ink chamber and for injecting the ink therefrom (Japanese Patent Disclosure (Kokai) No. 9622/73). A second example is a system having heating elements arranged in an ink chamber and adapted to heat the elements to generate bubbles in the ink chamber, thereby increasing the pressure of the ink and hence injecting it from a nozzle (Japanese Patent Publication No. 9429/81).
These systems are so-called on-demand systems for injecting ink as needed. The ink is not wasted, and the recording speed is relatively high. However, the conventional on-demand system has disadvantages. The nozzle tooling, arrangements of the piezoelectric and heating elements in the ink chamber, and the manufacture of the recording head are complicated. The manufacturing cost of the system is high. The system consumes much power thereby increasing the printing cost.
Among the ink-jet recording schemes, the on-demand system is suitable for increasing the recording speed. However, in order to increase the recording speed, the on-demand system is inferior to an electrophotographic system. In addition, the nozzles in the on-demand system tend to clog with dried ink when the system is not used for a long period of time.
According to one of the ink-jet recording systems, ink flies to record an image on recording paper without using the nozzles described above.
A typical example of this system is described in Japanese Patent Disclosure (Kokai) No. 132036/86. A heating element is arranged under ink level and energized to abruptly heat the ink. Bubbles are formed in the ink, and the ink flies upon breaking of the bubble.
According to this system, the nozzles do not clog with dried ink. However, since the heating element comprises an electric resistive element, several tens of microseconds to several milliseconds must be spent to sufficiently heat the electric resistive element. In addition, energy loss caused by heat conduction is also large, and thus heat efficiency is degraded. For this reason, the system is not suitable for high-speed recording.